THIRTY years from now, scientists will be growing whole hearts, livers and
even limbs in high-tech labs.
鈥淲e just need a reliable source of cells,鈥� says Anthony Atala, a urologist at
the Children鈥檚 Hospital in Boston. His team has grown artificial bladders for
beagles using tissue taken from normal dog bladders. The harvested tissue was
cultured until there was enough to 鈥渟eed鈥� a biodegradable 鈥渟caffold鈥濃�攁
growth surface in the shape of the organ. Transplanted into dogs, the new organs
served their recipients well for the 11 months of the experiment.
Atala鈥檚 organs did not use stem cells. But in future, embryonic stem cells
might be used to begin making a complex organ in the lab before the organ is
transplanted into the body to finish growing. The dog bladders took six weeks to
grow. A more complex organ, such as a kidney, might take several months.
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This approach is promising, says tissue engineer Robert Langer at the
Massachusetts Institute of Technology in Boston, because the body can overcome
two of the biggest difficulties faced in the lab鈥攑roviding an adequate
supply of oxygen and nutrients and a three-dimensional 鈥渇rame鈥� to give cells the
proper cues for growing into the right shape.
Clever tissue reconstruction techniques already make replacement ears and
noses. But the manipulation of stem cells will allow more complex organs to be
made. No more organ donor shortages, no more tissue rejection: medicine will be
revolutionised.